The present invention is concerned with a mechanism for the insertion of a weft yarn into the shed of a loom, as well as a loom, in particular an airnozzle loom with a profiled reed weft insertion channel. It has a yarn stopper arranged at the weft insertion side for braking the weft yarn after the insertion of a pre selected length of weft yarn into the shed. Further, a yarn holder device is fastened to the sley together with the reed in the region of the side of the shed where the weft yarn comes out for taking over the end of the weft yarn after completion of the weft yarn insertion.
CH 651 861 describes a yarn holder device which at the side of the shed where the weft yarn comes out exhibits a blowing nozzle which is directed into a mixing tube and is fastened to the sley to act transversely to the direction of run of the yarn and deflect the end of the weft yarn, and by which the weft yarn is stretched and held until the subsequent beat up and shed change. Springing back into the shed is thereby avoided. The disadvantages of these blowing and/or sucking nozzles--also known as stretching or gripping nozzles--are in particular the high consumption of air as well as the relatively large waste of yarn.
The reason for the high consumption of air is the relatively long holding time, i.e., the long duration of blowing or sucking for maintaining the flow of air until the weft yarn has been woven in and can no longer spring back into the shed. The relatively large waste of weft yarn arises from the necessity of exerting by the flow of high or low pressure air an adequately strong pull on the weft yarn, which is codetermined essentially by the surface of yarn exposed to the air flow. I.e., the smoother the surface of the yarn or respectively the thinner it is, the greater as a rule must the excess length of yarn and/or the level of the air pressure be chosen.